1. Field of the Invention
This invention relates to heat exchangers comprising a movable plate movable toward a frame with a plurality of heat transfer plates releasably clamped therebetween in an operational mode, and more specifically to such a heat exchanger with heat transfer plates unencumbered on its sides allowing lateral removal of heat transfer plates when the movable plate is withdrawn by action of a plurality of hydraulic rams and further having a positive lock securing the movable plate in its operational position.
2. Prior Art
It is known to have heat exchangers that comprise a plurality of heat transfer plates clamped into face-to-face contact by a movable plate urging the plurality of heat transfer plates against a frame. Previously, the plates have been urged together by spindles, or threaded rods, rotated by a drive motor. However, the spindles limited access for installation and removal of the heat transfer plates and a substantial portion of the heat exchanger had to be dismantled before heat transfer plates could be installed or removed. To remove the heat transfer plates for inspection and maintenance, it is advantageous to employ a mechanism that moves the movable plate away from the frame that leaves the heat exchanger plates unencumbered by tie rods or other system paraphernalia. Use of hydraulic rams have been employed that provide the advantageous access, however, hydraulic rams are known to lose pressure over time, therein allowing the plates to separate, causing a system failure as fluids intended to remain separate as they pass through the heat exchanger plates begin to seep through fluid seals in the heat exchanger plates causing cross contamination. In order to employ hydraulic rams to gain desired access for installation and removal of heat exchanger plates, it is necessary to employ a positive lock that is not dependent on pressure of the hydraulic rams to maintain the heat transfer plates in their operational position and condition.